Klamath River Lamprey: Facts & Habitat

About Klamath River Lamprey

Klamath River lamprey is a freshwater, parasitic lamprey restricted to the Klamath drainage of southern Oregon and northern California, including Klamath Lake. Adults occur in large rivers, lakes and impoundments.

NativeFresh2 states

Identification

The examined adults summarized by FishBase measure about 14–27 cm in total length. Preserved individuals are dark brown, including the underside, and have a spade-shaped tail. Detailed tooth arrangements around the mouth disc and tongue are important identification characters, especially where several lampreys share a drainage.

Sources: Entosphenus similis species summary

Feeding and reproduction

Adults feed parasitically on fishes. The cited summary does not identify those hosts, so a particular prey species should not be inferred. This lamprey reproduces once in its lifetime. Its movements occur within freshwater rather than requiring a sea-going adult stage.

Sources: Entosphenus similis species summary

Guide sources

Research reviewed 2026-10-19.

Entosphenus similis species summary — FishBase

Range

Where it lives

71.4%of mapped records

Share of 63 GBIF observation records with a state location, across 2 states.

Share of records by state

Habitat

Water and movement

Water: WoRMS records this species in fresh water.
Migration: Undetermined
Pattern: Potamodromous — migrates within fresh water
Disagreement: 2 published references do not agree on the pattern: Non-migratory, Potamodromous. The site shows every assignment rather than picking one.

Classification

Taxonomy

Kingdom: Animalia
Phylum: Chordata
Class: Cephalaspidomorphi
Order: Petromyzontiformes
Family: Petromyzontidae
Genus: Entosphenus
Species: Entosphenus similis
ITIS TSN: 914058
WoRMS AphiaID: 1012492
GBIF key: 2421359

Common questions about Klamath River Lamprey

What is the scientific name of Klamath River Lamprey?

The scientific name is Entosphenus similis, in the family Petromyzontidae. Classification follows ITIS.

Does Klamath River Lamprey live in fresh water or salt water?

WoRMS records this species in fresh water.

Where has Klamath River Lamprey been recorded in the United States?

GBIF has observations in 2 states, with the most records in Oregon, California. The map shows observation records, which do not establish the complete natural range.

Closest relatives